Composite firebrick



Oct. l13, 1959 C. BLISS ET AL COMPOSITE FIREBRICK Filed Oct. 50. 1953 INVENTORS s 5k l Y @A A A o T ,MWM .Mr c e Y A United States Patent i() AThe present invention relates to refractory walls and more particularly to a brick for said walls.

\In some furnaces the refractory walls are directly exposed to the heat of the re, so that the temperature of such refractory walls is raised to an extremely high degree. In other furnaces, the temperatures in the furnace chamber are extremely high which consequently cause high temperatures to exist in the refractory walls.

A maximum amount of heat radiation will then be obtained between the aforementioned refractory walls and the heat absorbing surfaces in the furnace. Since highgrade refractory rebrick withstands a high temperature, the furnace wall is generally made of such brick. By high-gradeV refractory rebrick, we mean a dense heavy lrefractory having high strength under high temperature but poor insulating properties. For example, in steam generators, bare refractory walls are made of high-grade iirebrick because such furnaces usually have high furnace chamber temperatures. On the other hand, in some oil heaters, exposed walls consist also of high-grade iirebrick because direct ame impingement thereon produces extremely high refractory temperatures.

Other applications of high rebrick result Whenever the brick must have a relatively high resistance to flame erosion, or possess high mechanical strength at high temperature.

A major disadvantage of the use of this high-grade fire-brick in a furnace wall is that the high surface temperature of the rebrick which exists on the furnace side produces a high temperature in the metal supports which support the refractory wall. Hence, more expensive alloy materials which are not affected by extremely high ternperatures must be used in'such refractory-wall supports. To overcome this difficulty, refractory walls consisting of lightweight insulating irebrick have been used. By lightweight insulating irebrick we mean a light porous refractory having a low strength under high temperature but good insulating properties.

-A major disadvantage of light-Weight insulating tirebrick is that it cannot withstand the erosive eifects of the llames on the brick surface due to the porous nature of the bricks. Also, the cutouts necessary in the irebrick to adapt it to the wall support members are generally weak because of the low mechanical strength of this type irebrick, even at relatively low temperatures.

lIn accordance with the present invention, a composite refractory wall rebrick is provided having a mechanically-strong and llame-resistant, high-grade refractory inner portion, a light-weight, insulating refractory middle portion having good insulation properties, and another mechanically-strong, high-grade refractory outer portion with cutouts therein for securing support members thereto.

The invention will be understood from the following description when considered in connection with the following drawings forming a part thereof and in which:

wall rebrick embodied in the present invention; and

ice

Fig. 2 is a sectional view taken on line 2--2 of` Fig. l.' Referring to the drawings, the .reference character ``1,0 designates a :composite refractorywall rebrickhaving a narrow, furnace-facing inner section-11, a wide. middle ortra-nsition section 1-2, and a relatively narrow outer seo-` tion 13. `Sections 1-1 and 13 of the rebr-ick are made-,of high-grade refractory `material such 1as dense, heavy: .refractory which material is resistant to arne-erosiomis mechanically strong, and wit-hstands a high'surface-temperature, as for example, tireclay mix or other well known Y material in the art possessing these properties. Section 12 of the frebrick is made of light-weight refractory material such as a porous refractory weighing approximately one-third as much as high-grade refractory, and having rather low strength but high-insulation properties, as for example, fire-clay mix to which is added sawdust or similar Well known materials used in the art. Outer section 13 of the rebrick is provided with a T-shaped cutout or slot 14 extending therethrough -to secure it to the support member, not shown, that holds the bricks in position in a refractory wall made of rebricks. A coating or strip of bonding material 15 is provided between the faces of middle sec/tion 12 and the faces of inner and outer sections 11 and 13, respectively, so that the component sections of the single rebrick will be joined together when made of dilerent materials not possessing adhesive characteristics with respect to one another.

The bricks of the present invention are formed into a furnace wall by mounting the bricks by their cutouts to support members which t or engage with the particular shapes of the cutout provided in the brick until the support members are covered and the wall is completed.

With the present invention, a composite frebrick is provided having: (1) A furnace-facing section of highgrade irebrick capable of withstanding high temperature while being resistant to flame erosion; (2) a middle section, insulating refractory-wall support members from an excessive temperature; and (3) a mechanically-strong outer section with cutouts therein for support members which support the iirebrick in a furnace wall.

inasmuch as various changes may be made in the particular form, location, and arrangement of parts of the apparatus disclosed and in the steps of the process and other sequences as disclosed without departing from the principles of the invention, it will be understood that the invention should not be limited excepting by the scope of the appended claims.

What is claimed is:

l. A unitary composite rebrick for use in a furnace comprising a middle portion of insulating material, a high-grade refractory portion on one side of and contiguous to said middle portion and facing the furnace, a second high-grade refractory portion on the opposite side of and contiguous to said middle portion, said second high-grade refractory portion being of substantial thickness to provide sucient body for a cutout means therein for securing the flrebrick to a support.

2. A unitary composite rebrick for use in a furnace, comprising a middle portion of insulating material, a high grade refractory portion on one side of and contiguous to said middle portion and facing the furnace, a second high grade refractory portion on the opposite side of and contiguous to said middle portion, said second refractory portion being of substantial thickness to provide suiiicient body for a T-shape cutout therein for securing the firebrick to a support.

3. A unitary composite irebrick for use in a furnace comprising a middle portion of insulating material, a highgrade refractory portion on one side of said middle portion and facing the furnace, a coating of bonding material between said middle and refractory portion, a second highgrade' refractory portion middle portion, another coating of bonding material between said second and middle portions, said second highgrade refractory p ortion being of substantial thickness to provide's'uicient'body for a cutout means in said second refractoryportion for 'securing the rebrick to a support. jf4 A lunitary composite irebrick foruse in a furnace, comprising a reclay-and sawdusfmiddle portion, a reclayfportion onone side of said middle portion and facing the furnace, al coating of bonding material between `said middle and reclay portions, a second reclay portion on the opposite side of said middle portion, another coat- 'ing of bonding'material between Vsaid middle and second reclay portions, said second reclay portion being of on the opposite side of said substantial thickness to provide suicient body for a T-shape cutout therein for securing the rebrick to a support.

References Cited in the ile of this patent UNITED STATES PATENTS 1,309,296 Marks July 8, 1919 1,430,027 Plantings Sept.V 26, 1922 1,448,684 Beecher et al. Mar'. 13, 1923 1,666,284 Gilchrist Apr.l 1,7,",1928 '1,709,035 Payne `Apr."16,'s1929 2,043,249 Jones June 9;-1936 2,242,434 Norton May 20, 1941 2,270,297v

Hensel Jan; 20, 1942 

